Interior Permanent Magnet (IPM) machines include a rotor assembly having a plurality of magnets of alternating polarity disposed around an outer periphery of the rotor assembly. The rotor assembly is rotatable within a stator which includes a plurality of windings. The rotor assembly magnetically interacts with the stator to generate rotation of the rotor assembly about a central axis of rotation.
Torque pulsation in electrical machines, often referred to as torque ripple, is a major contributor of machine noise and iron losses. Torque ripple is an effect seen in many electric motor designs, and refers to a periodic increase or decrease in output torque as an output shaft of the electric machine rotates. Torque ripple is typically measured as the difference in maximum and minimum torque during one complete revolution. The reduction or minimization of torque ripple in an electric machine is therefore an important design consideration during the design of the electric machine.